Inductively coupled CH4/H2 plasma etching process for mesa delineation of InAs/GaSb type-II superlattice pixels

Sona Das; Utpal Das

Inductively coupled CH₄/H₂ plasma etching process for mesa delineation of InAs/GaSb type-II superlattice pixels

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Author(s): Sona Das¹ and Utpal Das²
- Affiliations: 1: Department of Electronics and Communication Engineering , K.L University , Greenfields , Vaddeswaram , AP , India ;
  2: Department of Electrical Engineering , Indian Institute of Technology Kanpur , Kanpur 208016 , India
Source: Volume 14, Issue 7, 26 June 2019, p. 753 – 756
DOI: 10.1049/mnl.2018.5549 , Online ISSN 1750-0443

Received 11/09/2018, Accepted 27/02/2019, Revised 17/02/2019, Published 26/06/2019

An inductively coupled $C H 4 / H 2$ plasma etching process for delineation of InAs/GaSb type-II superlattice pixels is presented. An optimised $C H 4 / H 2$ etch recipe without alternate $O 2$ plasma cleaning step showed an etch rate as high as 0.11 μm/min that results in smooth vertical sidewalls for the type-II superlattice pixel arrays with 10 μm pitch size and 2.4 μm deep trenches. At 70 K, the dark current density for the mesa etched + SU-8 polymer passivated type-II superlattice photodiodes was found to be 0.11 A/cm² at an applied reverse bias voltage of 0.2 V. The activation energy of 13 meV obtained from the Arrhenius plot and a variable area diode array technique showed that the measured dark current is mainly attributed to bulk tunnelling current. This technique of mesa delineation for the type-II superlattice pixel arrays with small pitch size is a viable option in realising next-generation infrared focal plane arrays.

References

1. 1)
  - 15. Hoang, A.M., Dehzangi, A., Adhikary, S., et al: ‘High performance bias-selectable three-color short-wave/Mid-wave/long-wave infrared photodetectors based on type-II InAs/GaSb/AlSb superlattices’, Sci. Rep., 2016, 6, pp. 24144-1–24144-7.
2. 2)
  - 11. Sadasivan, V., Dagar, S., Das, U.: ‘Fabrication of low grass, smooth sidewall InGaAsP by methane–hydrogen inductively coupled plasma RIE through a metal lift-off mask patterned by e-beam lithography’, J. Vac. Sci. Technol. B, 2015, 33, pp. 051210-1–051210-5 (doi: 10.1116/1.4929437).
3. 3)
  - 4. Grover, R., Hryniewicz, J.V., King, O.S., et al: ‘Process development of methane–hydrogen–argon-based deep dry etching of InP for high aspect-ratio structures with vertical facet-quality sidewalls’, J. Vac. Sci. Technol. B, 2001, 19, pp. 1694–1698 (doi: 10.1116/1.1391252).
4. 4)
  - 17. Plis, E., Klein, B., Myers, S., et al: ‘Type-II InAs/GaSb strained layer superlattices grown on GaSb (111) B substrate’, J. Vac. Sci. Technol. B, 2013, 31, pp. 03C123-1–03C123-6 (doi: 10.1116/1.4798650).
5. 5)
  - 14. Lide, D.R. (Ed.): ‘CRC handbook of chemistry and physics, internet version 2005’ (CRC Press, Boca Raton, FL, 2005), pp. 9–55.
6. 6)
  - 19. Das, S., Das, U., Gautam, N., et al: ‘Type-II InAs/GaSb photodiode array pixel isolation by femto-second laser anneal’, Infrared Phys. Technol., 2016, 78, pp. 162–166 (doi: 10.1016/j.infrared.2016.07.023).
7. 7)
  - 17. Bouchoule, S., Boubanga-Tombet, S., Gratiet, L.L., et al: ‘Reactive ion etching of high optical quality GaN∕sapphire photonic crystal slab using CH4–H2 chemistry’, J. Appl. Phys., 2007, 101, (4), p. 43103 (doi: 10.1063/1.2433770).
8. 8)
  - 10. Plis, E.A., Kutty, M.N., Krishna, S.: ‘Passivation techniques for InAs/GaSb strained layer superlattice detectors’, Laser-Photonics Rev., 2013, 7, p. 45 (doi: 10.1002/lpor.201100029).
9. 9)
  - 10. Karouta, F.: ‘A practical approach to reactive ion etching’, J. Phys. D: Appl. Phys., 2014, 47, pp. 233501-1–233501-14 (doi: 10.1088/0022-3727/47/23/233501).
10. 10)
  - 3. Tan, S.L., Goh, Y.L., Das, D.S., et al: ‘Dry etching and surface passivation techniques for type-II InAs/GaSb superlattice infrared detectors’. Proc. SPIE, Toulouse, France, 2010, vol. 7838, pp. 783814-1–783814-8.
11. 11)
  - 7. Cheung, R., Thoms, S., Beamont, S., et al: ‘Reactive ion etching of GaAs using a mixture of methane and hydrogen’, Electron. Lett., 1987, 23, pp. 857–859 (doi: 10.1049/el:19870606).
12. 12)
  - 13. Mathews, S., Schuler-Sandy, T., Kim, J.S., et al: ‘In situ flashes of gallium technique for oxide-free epiready GaSb (100) surface’, J. Vac. Sci. Technol. B, 2017, 35, pp. 02B114-1–02B114-4 (doi: 10.1116/1.4978604).
13. 13)
  - 8. Diniz, J.A., Swart, J.W., Jung, K.B., et al: ‘Inductively coupled plasma etching of In-based compound semiconductors in CH4/H2/Ar’, Solid State Electron., 1998, 42, pp. 1947–1951 (doi: 10.1016/S0038-1101(98)00136-1).
14. 14)
  - 2. Höglund, L., Asplund, C., von Würtemberg, R.M., et al: ‘Advantages of T2SL: results from production and new development at IRnova’. Proc. SPIE, Baltimore, Maryland, USA, 2016, vol. 9819, pp. 98190Z-1–98190Z-10.
15. 15)
  - 1. Rogalski, A., Martyniuk, P., Kopytko, M.: ‘Inas/GaSb type-II superlattice infrared detectors: future prospect’, Appl. Phys. Rev., 2017, 4, pp. 031304-1–031304-21 (doi: 10.1063/1.4999077).
16. 16)
  - 6. Werking, J., Schramm, J., Nguyen, C., et al: ‘Methane/hydrogen-based reactive ion etching of InAs, InP, GaAs, and GaSb’, Appl. Phys. Lett., 1991, 58, pp. 2003–2005 (doi: 10.1063/1.105046).
17. 17)
  - 16. Kim, H.S., Plis, E., Khoshakhlagh, A., et al: ‘Performance improvement of InAs/GaSb strained layer superlattice detectors by reducing surface leakage currents with SU-8 passivation’, Appl. Phys. Lett., 2010, 96, pp. 033502-1–033502-3.
18. 18)
  - 18. Gautam, N., Myers, S., Barve, A.V., et al: ‘Barrier engineered infrared photodetectors based on type-II InAs/GaSb strained layer superlattices’, IEEE J. Quantum Electron., 2013, 49, pp. 211–217 (doi: 10.1109/JQE.2012.2236643).
19. 19)
  - 5. Bi, Y., Gaillardon, P., Hu, X.S., et al: ‘Leveraging emerging technology for hardware security - case study on silicon nanowire FETs and graphene SymFETs’. IEEE 23rd Asian Test Symp., Hangzhou, China, 2014, pp. 342–347.

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Inductively coupled CH₄/H₂ plasma etching process for mesa delineation of InAs/GaSb type-II superlattice pixels

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